Abstract
A total of 614 upward throughgoing muons of minimum energy 1.6 GeV are observed by Super-Kamiokande during 537 detector live days. The measured muon flux is [1.74±0.07(stat)±0.02(sys)]×10-13cm-2s-1sr-1 compared to an expected flux of [1.97±0.44(theor)]×10-13cm-2s-1sr-1. The absolute measured flux is in agreement with the prediction within the errors. However, the zenith-angle dependence of the observed upward throughgoing muon flux does not agree with no-oscillation predictions. The observed distortion in shape is consistent with the vμ⟷vτ oscillation hypothesis with sin22θ> 0.4 and 1×10-3Δm2<1×10-1eV2 at 90% confidence level.
Original language | English (US) |
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Pages (from-to) | 2644-2648 |
Number of pages | 5 |
Journal | Physical review letters |
Volume | 82 |
Issue number | 13 |
DOIs | |
State | Published - 1999 |